Grimm is often a game of “we know they know we know” with characters like Hank and Juliet gradually getting in the loop about Nick’s Grimm life and the Portland detective learning the true identity of his boss. Now it’s Monroe’s turn to learn about something that’s been kept from him. In tomorrow’s episode, Nick finally shows Monroe the mysterious key the Royals are determined to get their hands on.

EW has an exclusive clip from this moment, which picks up right after one of those inevitable, unfortunate roomie encounters that even happen to a Grimm and a Wesen. “There is a very funny scene where I perhaps walk in on a moment I shouldn’t have walked in on,” actor David Giuntoli (Nick) told reporters on Monday.

Check out the clip below:

It’s not just Monroe who seems to know something about the key – Renard fills Nick in on the history behind it too.

“The Captain will be giving me a stern Captain-esque lecture about my history and the Royals, and why they want me and me in particular,” Giuntoli said.

The episode, called “Endangered,” has Nick investigating weird cow mutilations and reports of glowing creatures in Portland.

“We’re going to be seeing something very paranormal – I want to say almost X-Files-y – that is not a standard Grimms fairy tale, almost like we’re dealing with what people on Earth think are aliens, but we tell you what they really are, the real explanation for them,” Giuntoli teased.

Tomorrow’s episode marks the NBC show’s first time airing on Tuesday night, a move from Fridays announced earlier this month. Grimm will now have a powerful lead-in from The Voice. NBC also recently renewed Grimm for a third season, though it is yet to be determined whether the show will stay in its new Tuesday home or move back to Fridays come fall.

“I think that NBC is showing a lot of faith in Grimm by moving us to Tuesday nights,” Giuntoli said of the move. “We’re very excited to expose Grimm to an entirely new audience and scare and befuddle a whole new segment of the population.”

“Endangered,” episode 19 of Grimm’s second season, will air at 10 p.m. on Tuesday, April 30.